Cyclic response of double-tee connections without shear tabs

This study investigates the cyclic behavior of double-tee moment connections without shear tabs using European steel profiles. A three-dimensional finite element model was developed in ANSYS Workbench and validated against experimental results. The model included material and geometric nonlinearities, contact interactions, bolt pretension, and a Chaboche kinematic hardening model to simulate cyclic inelastic behavior. A parametric study examined the effects of T-flange and T-stem thickness, bolt spacing, continuity and doubler plates, reinforcing plates, beam web stiffeners, and circular web openings. Connection performance was evaluated in terms of rotational stiffness, moment capacity, energy dissipation, stress distribution, and plastic hinge formation. Artificial neural network (ANN) models were also developed to predict monotonic and cyclic response parameters. The results show that T-flange thickness and local reinforcement details most significantly improve seismic performance, while bolt spacing has a limited influence. ANN models provided accurate and efficient predictions for preliminary connection assessment.